While distributed architecture is highly successful in achieving scaling and performance, it introduces significant troubleshooting issues. In a distributed virtual network environment, the network infrastructure comprises different logical resources (LR) and different types of physical endpoints (PE). The typical situation in this distributed virtual network is that a logical resource (such as a logical switch or router) may physically span multiple physical endpoints. While this distributed structure enhances the availability and scalability of the LRs, it often introduces difficulty when one has to troubleshoot or debug the system.
While it is easy to extend and scale a logical network that is distributed over a physical network, it may be difficult to troubleshoot the logical network when fault occurs. Typically, a user has to log into different physical endpoints to troubleshoot the distributed system. This can be difficult for the user for the following reasons: (1) it is difficult for the user to remember different user passwords for different PEs; (2) it is difficult for the user to remember which logical resources are in which PEs; (3) it is difficult for the user to remember which terminal (for CLI) or window (for GUI) is connected to which PE; (4) the command history in different terminals cannot be reused; and (5) IP addresses are mostly meaningless to a human user and hard to memorize or analyze.